Sample Color values of input averaging within a box size

AutoExposure.nk

Group {
 name AutoExposure
 addUserKnob {20 User}
 addUserKnob {41 wb T ColorMatch.wb}
 addUserKnob {41 dst_color l dst T ColorMatch.dst_color}
 addUserKnob {22 calc T "n = nuke.thisNode()\nnuke.root().begin()\nn.begin()\nct = nuke.toNode('CURVETOOL')\nct\['intensitydata'].clearAnimated()\nt = nuke.frame()\nnuke.execute(ct, t, t)" +STARTLINE}
 addUserKnob {26 ""}
 addUserKnob {41 intensitydata T CURVETOOL.intensitydata}
 addUserKnob {41 sample T ColorSampler.sample}
 addUserKnob {26 ""}
 addUserKnob {41 center T ColorSampler.center}
 addUserKnob {41 size T ColorSampler.size}
 addUserKnob {41 area T ColorSampler.area}
 addUserKnob {41 percentage T ColorSampler.percentage}
}
 Input {
  inputs 0
  name Input
  xpos -200
  ypos -550
 }
 Dot {
  name Dot1
  label " "
  note_font "Helvetica Bold Bold Bold Bold Bold"
  note_font_size 24
  note_font_color 0xa5a5a501
  xpos -166
  ypos -438
 }
set Nbfbfcfd0 [stack 0]
 NoOp {
  name SamplerPython
  xpos -360
  ypos -370
  addUserKnob {20 Sampler}
  addUserKnob {15 area}
  area {{center.x-(size.w/2) x1 2956.858605} {center.y-(size.h/2*input.pixel_aspect) x1 1832.641304} {center.x+(size.w/2) x1 2839.141395} {center.y+(size.h/2*input.pixel_aspect) x1 2037.358696}}
  addUserKnob {12 center}
  center {{width/2} {height/2}}
  addUserKnob {14 size R 0 100}
  size {{width*percentage} {height*percentage}}
  addUserKnob {7 percentage}
  percentage 0.2
  addUserKnob {18 sample}
  sample {{"\[python -execlocal channel\\ =\\ \\\"red\\\"\\nn\\ =\\ nuke.thisNode()\\ncenter\\ =\\ n\\\['center'\\].getValue()\\nsize\\ =\\ n\\\['size'\\].getValue()\\nsample\\ =\\ n.sample(channel,\\ center\\\[0\\],\\ center\\\[1\\],\\ size\\\[0\\],\\ size\\\[1\\])\\nret\\ =\\ sample]"} {"\[python -execlocal channel\\ =\\ \\\"green\\\"\\nn\\ =\\ nuke.thisNode()\\ncenter\\ =\\ n\\\['center'\\].getValue()\\nsize\\ =\\ n\\\['size'\\].getValue()\\nsample\\ =\\ n.sample(channel,\\ center\\\[0\\],\\ center\\\[1\\],\\ size\\\[0\\],\\ size\\\[1\\])\\nret\\ =\\ sample]"} {"\[python -execlocal channel\\ =\\ \\\"blue\\\"\\nn\\ =\\ nuke.thisNode()\\ncenter\\ =\\ n\\\['center'\\].getValue()\\nsize\\ =\\ n\\\['size'\\].getValue()\\nsample\\ =\\ n.sample(channel,\\ center\\\[0\\],\\ center\\\[1\\],\\ size\\\[0\\],\\ size\\\[1\\])\\nret\\ =\\ sample]"}}
  addUserKnob {6 sample_panelDropped l "panel dropped state" -STARTLINE +HIDDEN}
 }
push $Nbfbfcfd0
 Group {
  name ColorMatch
  tile_color 0x7aa9ffff
  xpos -200
  ypos -298
  addUserKnob {20 ColorMatch}
  addUserKnob {18 ic}
  ic {{parent.CURVETOOL.intensitydata} {parent.CURVETOOL.intensitydata} {parent.CURVETOOL.intensitydata}}
  addUserKnob {6 ic_panelDropped l "panel dropped state" -STARTLINE +HIDDEN}
  addUserKnob {7 wb}
  addUserKnob {6 input_color_panelDropped l "panel dropped state" -STARTLINE +HIDDEN}
  addUserKnob {18 exposure R -4 4}
  exposure {0 0 0}
  addUserKnob {6 exposure_panelDropped l "panel dropped state" -STARTLINE +HIDDEN}
  addUserKnob {26 ""}
  addUserKnob {18 src_color l src}
  src_color {{"ic*wb + (ic.r+ic.g+ic.b)/3*(1-wb)"} {"ic*wb + (ic.r+ic.g+ic.b)/3*(1-wb)"} {"ic*wb + (ic.r+ic.g+ic.b)/3*(1-wb)"}}
  addUserKnob {6 src_color_panelDropped l "panel dropped state" -STARTLINE +HIDDEN}
  addUserKnob {18 dst_color l dst}
  dst_color 0.35
  addUserKnob {6 dst_color_panelDropped l "panel dropped state" -STARTLINE +HIDDEN}
  addUserKnob {18 multiply t result}
  multiply {{Multiply.value} {Multiply.value} {Multiply.value}}
  addUserKnob {6 multiply_panelDropped l "panel dropped state" -STARTLINE +HIDDEN}
  addUserKnob {26 ""}
  addUserKnob {7 mix}
  mix 1
 }
  Input {
   inputs 0
   name Input
   xpos -40
   ypos 62
  }
  Multiply {
   channels rgb
   value {{"pow(2, parent.exposure) * parent.dst_color / parent.src_color"} {"pow(2, parent.exposure) * parent.dst_color / parent.src_color"} {"pow(2, parent.exposure) * parent.dst_color / parent.src_color"} 1}
   mix {{parent.mix}}
   name Multiply
   xpos -40
   ypos 134
  }
  Output {
   name Output
   xpos -40
   ypos 206
  }
 end_group
set Nf19906a0 [stack 0]
 Output {
  name Output
  xpos -200
  ypos -190
 }
push $Nbfbfcfd0
 NoOp {
  name ColorSampler
  xpos -360
  ypos -442
  addUserKnob {20 ColorSampler}
  addUserKnob {15 area}
  area {{center.x-(size.w)/2} {center.y-(size.h/2*input.pixel_aspect)} {center.x+(size.w/2)} {center.y+(size.h/2*input.pixel_aspect)}}
  addUserKnob {12 center}
  center {{width/2} {height/2}}
  addUserKnob {14 size R 0 100}
  size {{width*percentage} {height*percentage}}
  addUserKnob {7 percentage}
  percentage 0.5
  addUserKnob {18 sample}
  sample {{"\[sample this.input r center.x center.y size.w size.h]"} {"\[sample this.input g center.x center.y size.w size.h]"} {"\[sample this.input b center.x center.y size.w size.h]"}}
  addUserKnob {6 sample_panelDropped l "panel dropped state" -STARTLINE +HIDDEN}
 }
push $Nbfbfcfd0
 CurveTool {
  ROI {{parent.ColorSampler.area} {parent.ColorSampler.area} {parent.ColorSampler.area} {parent.ColorSampler.area}}
  autocropdata {512 389 1536 1167}
  intensitydata {{curve x9 0.7911825557} {curve x9 0.7540757797} {curve x9 0.6213526972} 1}
  name CURVETOOL
  xpos -360
  ypos -298
 }
push $Nf19906a0
 Viewer {
  frame_range 1-100
  colour_sample_bbox {-0.2019627392 -0.1319999993 0.202000007 0.1309068277}
  viewerProcess "RRT (ACES)"
  name Viewer1
  xpos -367
  ypos 33
  addUserKnob {20 Lock}
  addUserKnob {6 lock_all_buffers l "lock all buffers" -STARTLINE}
  addUserKnob {6 lock_buffer_1 l "lock buffer 1" +STARTLINE}
  addUserKnob {6 lock_buffer_2 l "lock buffer 2" +STARTLINE}
  addUserKnob {6 lock_buffer_3 l "lock buffer 3" +STARTLINE}
  addUserKnob {6 lock_buffer_4 l "lock buffer 4" +STARTLINE}
  addUserKnob {6 lock_buffer_5 l "lock buffer 5" +STARTLINE}
  addUserKnob {6 lock_buffer_6 l "lock buffer 6" +STARTLINE}
  addUserKnob {6 lock_buffer_7 l "lock buffer 7" +STARTLINE}
  addUserKnob {6 lock_buffer_8 l "lock buffer 8" +STARTLINE}
  addUserKnob {6 lock_buffer_9 l "lock buffer 9" +STARTLINE}
  addUserKnob {6 lock_buffer_0 l "lock buffer 0" +STARTLINE}
 }
end_group